Summer Whiting in Lake Ontario - A Microscopic Perspective
Ann Arbor, MI — What causes the milky water color often observed in the summer in Lake Ontario? A phenomenon so profound that can be even seen from space (satellite imagery).
The milky waters were a result of calcium carbonate (calcite) precipitation. The phenomenon, fittingly referred to as "whiting", has long been documented to occur frequently in the summer months in Lake Ontario (also in Lake Michigan and Lake Erie).
"In addition to warm temperature and high concentrations of calcium and carbonate ions, nucleation sites for calcite crystallization are critical for the whiting to commence," says Feng Peng, a Senior Scientist at the Upstate Freshwater Institute (Syracuse, New York). "Our research, employing a unique technique, has uncovered what were underneath the calcite particles in Lake Ontario."
Suspended particles were collected during a whiting event and retained on polycarbonate filter membranes. Examining these particles before and after dilute acid treatment (to dissolve away calcite precipitated on nucleation sites) with a scanning electron microscope, Feng Peng and Steven Effler found that primarily, algae in the micrometer size range were underneath the calcite coating; clay mineral particles could also served as nuclei. This result is par of the findings of the authors’ research project to study the optical variability and the light-scattering effects of mineral particles in Lake Ontario. The authors also documented a successful application of a two-component (organic and mineral) approach to model particulate scattering and the implications of whiting events in reducing water clarity.
Original Publication Information
Results of this study, "Characterizations of the light-scattering attributes of mineral particles in Lake Ontario and the effects of whiting," are reported by Feng Peng and Steven Effler in the Volume 37, No. 4, of the Journal of Great Lakes Research, published by Elsevier, 2011.
Contacts
For more information about the study, contact Feng Peng, Upstate Freshwater Institute, PO Box 506, Syracuse, New York 13206; fpeng@upstatefreshwater.org, (315)-431-4962.
For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, Environment Canada, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; jglr@ec.gc.ca; (306) 975-5310.
Since 1967, IAGLR has served as the focal point for compiling and disseminating multidisciplinary knowledge on North America's Laurentian Great Lakes and other large lakes of the world and their watersheds. In part, IAGLR communicates this knowledge through publication of the Journal of Great Lakes Research, available to members in print and electronic form. A searchable archive of the journal is available online and includes the abstracts of articles from the journal's inception in 1975 through the most recent issue. In addition, complete articles are available to members who have signed up for an electronic subscription.